Radiation-Pressure Blowout in a Debris Disk

Debris disks around other stars — dusty analogues of our own Kuiper Belt — are sustained by a runaway collisional cascade: planetesimals in a narrow belt keep smashing each other into ever-smaller fragments, feeding a steady stream of fresh micron-sized dust. This simulator follows what happens to that dust the instant it is born. Each grain inherits the circular-orbit velocity of the rubble it came from, but starlight pushes outward on it while gravity pulls inward, and the balance of those two forces — the parameter β — decides its fate: a bound, increasingly eccentric ellipse for larger grains, or a one-way hyperbolic ejection for anything smaller than the blowout size. Adjust grain size and the star's luminosity-to-mass ratio and watch the belt's freshly ground dust either settle into a puffed-up halo or stream away entirely, exactly as observed in real systems like β Pictoris and Fomalhaut.